Here we present preliminary results of a project funded by the Italian MIUR that focuses on the marine paleo-ecosystem responses to climate variations in the Eemian time period (130--110 ky BP). It has long been established that climate in the Quaternary is characterised by the alternation of glacial/interglacial periods, linked with cyclical changes in the Earth/Sun orbital parameters. Such climate variations have strong influence on marine ecosystem through the modification of physico-chemical parameters in the water column: they are in fact testified by changes in planktonic assemblages composition and by temperature-driven variations in the oxygen isotope fractionation on foraminiferal tests. The Eemian interval represents the warmest period of the last 150 kyrs BP and its recorded temperatures were inferred to be some degree higher than present day conditions. Because of these climatic variations, paleoceanography and paleoproductivity of the basin markedly changed, often resulting in the deposition of peculiar carbon-rich sediment layers, called sapropels. Among them sapropel S-5 deposited during the Eemian period and it is found to be finely laminated at some locations; this offers the opportunity to study climate-related paleoecosystem modifications in great detail. In particular the project will focus on 3 main scientific objectives: 1) to identify, by the integrated study of paleobiological phyto- and zooplankton data, paleo-ecosystem variations in the eastern Mediterranean, related to climate changes during the Eemian period; 2) to define the main physical parameters in the Mediterranean marine ecosystem during the Eemian, through the creation of a core-top biological data base and the use of MAT and RAM methods. Finally physical and paleobiological obtained data will be compared with the circum-mediterranean on-land evidences of climate change and with the world-wide records from oceanic sediments and polar ice cores; 3) to carry out numerical simulations of the effects of climate changes within the Eemian on the physical and biogeochemical characteristics of the Mediterranean Sea, using reconstructions of surface forcings: for such aim, an ecosystem model, based on present day and Holocene simulations, will be developed.
The dynamic of the Mediterranean paleoecosystem during the Eemian interval
Capotondi L;
2003
Abstract
Here we present preliminary results of a project funded by the Italian MIUR that focuses on the marine paleo-ecosystem responses to climate variations in the Eemian time period (130--110 ky BP). It has long been established that climate in the Quaternary is characterised by the alternation of glacial/interglacial periods, linked with cyclical changes in the Earth/Sun orbital parameters. Such climate variations have strong influence on marine ecosystem through the modification of physico-chemical parameters in the water column: they are in fact testified by changes in planktonic assemblages composition and by temperature-driven variations in the oxygen isotope fractionation on foraminiferal tests. The Eemian interval represents the warmest period of the last 150 kyrs BP and its recorded temperatures were inferred to be some degree higher than present day conditions. Because of these climatic variations, paleoceanography and paleoproductivity of the basin markedly changed, often resulting in the deposition of peculiar carbon-rich sediment layers, called sapropels. Among them sapropel S-5 deposited during the Eemian period and it is found to be finely laminated at some locations; this offers the opportunity to study climate-related paleoecosystem modifications in great detail. In particular the project will focus on 3 main scientific objectives: 1) to identify, by the integrated study of paleobiological phyto- and zooplankton data, paleo-ecosystem variations in the eastern Mediterranean, related to climate changes during the Eemian period; 2) to define the main physical parameters in the Mediterranean marine ecosystem during the Eemian, through the creation of a core-top biological data base and the use of MAT and RAM methods. Finally physical and paleobiological obtained data will be compared with the circum-mediterranean on-land evidences of climate change and with the world-wide records from oceanic sediments and polar ice cores; 3) to carry out numerical simulations of the effects of climate changes within the Eemian on the physical and biogeochemical characteristics of the Mediterranean Sea, using reconstructions of surface forcings: for such aim, an ecosystem model, based on present day and Holocene simulations, will be developed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
